Structural element



Sept. 14, 1943. M. K, wElLL ET A1. 2,329,366 'l STRUCTURAL ELEMENT Filed April 29, 1940 2 sheets-sheet 1 BY @MLM/z2 ATTORNEY Sept. 14, 1943. vM. K. WEILL ETAL STRUCTURAL ELEMENT Filed April 29, 1940 2 s'heeis-sneet 2 INVENToRs /VE/ z//uf /f #VE/LL.

f7/WM5 mur/vae ATTORNEY Parenteel sept.' 14, 1943 STRUCTURAL ELEMENT Melville K. Weill and Etienne Mautner, New York, N. Y., asslgnors-to Skydyne Inc., New York, N. Y., a corporatlonof New York Application Apro zo, 1940, serial No. 332,194

' 'z claims. (c1. Izii-91) This invention relates to structural elements useful generally in the arts where strength,

l rigidity and lightness are desirable and more particularly in the art of, airplane construction.

In the accompanying drawings: Fig. 1 is a sectional view of one form of the invention. Figs. 2, 3, ,3A and 4 are views of other forms, also shown in. section. Fig. 5 is a iiatwise view of the structure shown in Fig. 4 with part of one layer ofthe surface material removed and partly in section on the line 6-5 of Fig. 4. Fig. 6 is a sectional view of one form of a pin or post. Fig. 7 is an alternative structure shown in section. Fig. 8 is a sectional view taken on line 8-8 of Fig. 7, shown with one surface layer removed. Fig. 9 is a sectional view of a structure like that of Fig. 'l except that it is bent to show the'form taken at the forward edge of an airplane wing. Fig. 10 is a. view of another alternative structure, also in section. Figs. 1l and 11A are views of other alternative structures, also in section. Fig. 12 is a flatwise view of the structure of Fig. 11, shown with one surface layer removed. Fig. 13 is a perspective view partly in section and ypartly fragmentary to show the manner in which a structure' like that of Figs. 4 and 5, for example, may be formed into a wing for an airplane.` And Fig. 14 is an enlarged view, in section, of the receding edge of the wing structure.

In the drawings the character I represents a layer or .block of light weight material, which may be of pulverized or granular cork held in mass by a suitable binder such as glue, and 2 is a wire mesh screen imbedded therein for strengthening the layer laterally. On either side of this cork-screenI combination there may be placed for stiiIening purposes (Fig. 2, etc.) surface layers of plywood 3. In Figs. 1 and 2 the layer of cork is thin, being of just sufilcient thickness to cover the screen in order to provide cushion against abrasive action or cutting of the wire mesh into the surface of an adjacentlayer. In Fig. 3 the cork layer is thick enough to lend additional strength to bending forces to which the structure may be subjected. In Fig. 3A two wire mesh screens are imbedded in the cork layer,

' each as close as is practical to the surface thereof which still further increases the strength of the structure over that shown in Fig. 3 and with only aminimum increase in weight.

As shown in Fig. 4 the cork layer is of such shape thatopen spaces or grooves 4 are provided to reduce the bulk of the material and ltherefore to lessen its total weight, without substantially reducing its strength. The resistance of this element to crushing forces is enhanced by posts 5,

which may be wood pins or take other forms such as that of al metal tube 8 (Fig. 6) flared at eitheror both ends. The ends of such posts preferably closely approach but normally do not quite contact the outer layers of plywood.

In the alternative structures shown in Figs. 7, 8 and 9 the screen is imbedded in a thin layer of cork, such as that of Fig. 2, and placed between strips of the veneer which makeup the plywood surface covering. As the screen does not come in direct contact with the plywood it will not weaken the latter by abrasion or cutting.

'This construction is shown more clearly in the enlarged view, Fig. 10, where, however, the

`strengthening screen and thin cork combination is used only in one of the two outer'plywood coverings. The other covering layer in this instance is plain plywood.

In Figs. 11, 11A and l2, which show the preferred structure, the screen is located intermediate two arrays of mutually registering blocks 1 of cork. The posts 5 or 6 are inserted through some or all of these blocks and the intermediate screen.

When used in airplane wings, as shown in Figs. 13 and 14, the meeting edges of the folded structure are securely held in place by ends 8 which may be made up of two complimentary strips 9 and Il) of light weight material suchas spruce glued together and held from lateral displacement by a single longitudinal round rod II of strong material such as birch Fig. 14. Where the aerofoil is of deep cross-section the complementary strips 9 and IIJ are provided with an additional longitudinal rod II of birch as. shown in Fig. 13. 'Il'his end section 8 is shaped to register with extensions I2 of the outer layer of plywood. Another rod I3 oi' birch is inserted between the edges of the wing and in abutment with the ends B. All of these parts are held together by glue.

We claim: f l. A structural sheet comprising a layer of p rticles of light weight cellular material comressed with a binder and having a wire mesh screen embedded therein, said layer having surface depressions, in combination with alayer ofl stiifening material attached to said rst mentioned layer and overlapping said depressions.

2. A' structural element comprising an inner layer of light weight compressible material, outer layers of stiffening material, and an array of rigid blocks of the `said compressible material spaced apart, each of said blocks enclosing one of said 3. Theelement according to claim 2, wherein the said posts are or tubular formation.

4. The element according to claim 2, wherein i the ends of the said posts are enlarged 5. A structural sheet made up of adJoined layers, one oi' which comprises a plurality of blocks of compressibie material spaced apart and QIh collectively reinforced by a wire screen embedded in said blocks and extendingvinto the spaces therebetween, and another of which layers is plywood.

6. The element according to claim 5, together with an array of posts transversely piercing the said blocks and the said screen.

7. A structural element comprising an inner layer of compressed particles of light weight material and outer stin'ening layers, one at leastof said outer layers being made up of strips of veneer spaced apart and enclosing a wire mesh screen embedded in another layer of such material.

. IMELVILLEK.WEILL. ETIENNE MA'UTNER. 

